The engine on my 2000 EX-L coupe 4 cylinder 5 speed makes a loud diesel like sound when I start it. The sound doesn’t go away until I’ve been driving at least 2-3 miles in the city. By the time I get to work (17 highway miles later), the sound is basically gone. It’s loudest between 800-1500 rpms.

I performed a valve adjustment today. Most of the exhaust valves were too tight, and most of the intake valves were too loose. They are all in spec now. The engine runs smoother, but the diesel sound is still there. It seems to be coming from the bottom of the engine.

Did some searching on this forum and on google, and it seems that these engines have some amount of audible piston slap that is completely normal. I normally associate audible piston slap with bottom end work.

Is this diesel sound normal, or should I be concerned about some upcoming major repairs? Or what could it be?

 

Check all exhaust heat shields to be sure they are securely fastened.

AC idler bearing and tensioner (not sure if you have one) can also cause rattling sounds. Check them.

good luck

 

You might want to check your exhaust manifold and see if any bolts are cracked or broke that hold it in place.

 

My car ticks really bad on cold starts but goes away when engine warms up. This is way worse in very cold weather. So I keep the rpms as low as possible till it warms up. If it doesn't go away when the engine warms up, I would worry, otherwise I would drive it till it blows. Piston slap sounds like random knocks with no rythim. Ticks are ticks that go with the rpms. hope this helps.